The purpose is to find out if Icleen IQAir, HEPA-filter air cleaners with high capacity and pre-set speed functions, have a beneficial effect on patients with asthma and allergy to dogs.

Air cleaners will be installed in the bedrooms and living rooms in the homes of children and adolescents aged 8-17 years at the study entry, with allergy to dogs, but not to house dust mites.

The investigators will look upon the significance of this study, and of a previous study with a similar design and the same main parameters to find out if this trial supports the results of the first trial by the same project leader, or makes it likely that the seemingly beneficial effects of the first study occurred by chance.

Two air cleaners are installed in the patient's room, one in his bedroom, and one in the living room. The cleaners can be run at 5 different speeds: Speed 1 filtrates 60m3 of air per hour, speed 2 filtrates 90 m3 per hour, speed 3 filtrates 130 m3 per hour, speed 4 filtrates 240 m3 per hour, and speed 5 filtrates 380 m3 per hour. A timer-on period can be pre-set for every day of the week, but the cleaner can be run even in the timer-off period, at a speed pre-set and different from the timer-on period. Different timer-on off periods cannot be selected for different days, but the different days of the week can be pre-set to apply timer-on periods or not.

Other Name: Health Pro

Placebo Comparator: Placebo air cleaner

Two Icleen IQAir air cleaners with placebo filters supplied

Device: IQAir Allergen 100 Air cleaners

Two air cleaners are installed in the patient's room, one in his bedroom, and one in the living room. The cleaners can be run at 5 different speeds: Speed 1 filtrates 60m3 of air per hour, speed 2 filtrates 90 m3 per hour, speed 3 filtrates 130 m3 per hour, speed 4 filtrates 240 m3 per hour, and speed 5 filtrates 380 m3 per hour. A timer-on period can be pre-set for every day of the week, but the cleaner can be run even in the timer-off period, at a speed pre-set and different from the timer-on period. Different timer-on off periods cannot be selected for different days, but the different days of the week can be pre-set to apply timer-on periods or not.

Children and adolescents between 8 and 17 years of age at the start of the trial (born after 01 March '88, but before 01 September '97).

Bronchial asthma, diagnosed by a physician, and confirmed by a physician at a paediatric department of a Norwegian Hospital.

Allergy against dogs, confirmed by skin prick test. Average infiltrate at least 4 millimetres against dog, diagnosed by a new skin prick test at entry. For details about skin prick test, see attachment no. 6.

Having had nose or breathing symptoms by contact with dogs, when no drugs against asthma or allergy have been taken.

Able to co-operate at cold air hyperventilation test and spirometry (see attachment no. 2).

Given written consent (by parents of children below 12; by parents and child when above 12, but below 16; by patient when above 16).

Exclusion Criteria:

Positive house dust mite skin prick test, with a more than 3 mm infiltrate.

Having taken oral beta-2-agonists or theophylline preparations for the last 2 weeks before trial start, or oral steroids for the last 3 months before start of the trial.

Active smoking.

Dogs or cats in the home.

Staying away from the home continuously for more than 14 days in the trial period or during the last month before trial start.

Being an in-patient in a special department or institution for asthma and allergy in the trial period or the last 3 months before the trial.

Having another chronic disease that can influence the results of ECP or cold air hyperreactivity tests.

Other types of mechanical ventilation or air filtration systems in the homes, except for those for kitchen stoves.

Contacts and Locations

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For general information, see Learn About Clinical Studies.

Please refer to this study by its ClinicalTrials.gov identifier: NCT00220753